Caterpillar Inc.

Thomas G Ausman

Ronald Dean Shinogle

Michael Patrick Harmon

Michael T Zimmer

Scott Richard Schuricht

Manas R Satapathy

Douglas E Longman

Alan Ray Stockner

Steven Y Tian

Lianghe Zuo

Jeffrey C Huang

Jon E Kasen

Michael A Flinn

Charles R Riggert

Frederick A Camplin

Fred A Camplin

Timothy E Delaney

Eric M Bram

John G Ertel

An actuation fluid control valve for a hydraulically actuated fuel injector has a valve body having an inlet seat, a bore having a bore axis and a bore wall, an actuation control cavity, a low pressure actuation fluid drain, an actuation fluid inlet for admitting high pressure actuation fluid to the bore from outside the fuel injector, an inlet seat at a border between the actuation control cavity and the bore, and a drain seat at a border between the actuation control cavity and the actuation fluid drain. An actuator is attached with the valve body. An actuation valve member has an inlet pin surface partially defining a fluid entry chamber within the bore and is slidably disposed in the bore in response to the actuator between a first position in which the actuation control cavity is open to the actuation fluid inlet via the fluid entry chamber and the actuation valve member is being held against the drain seat such that the actuation control cavity is fluidly isolated from the actuation fluid drain, and a second position in which the actuation control cavity is open to the actuation fluid drain and the actuation valve member is being held against the inlet seat such that the actuation control cavity is fluidly isolated from the actuation fluid inlet.

Hydraulically actuated fuel injector with seated pin actuator

A hydraulically actuated fuel injector has an electronically controlled actuator that moves an actuation valve member. The actuator can position the actuation valve member at one position to cause pressurization of fuel in a nozzle chamber for fuel injection, and at another position to hydraulically bias a check to halt fuel injection while maintaining full fuel pressure in the nozzle chamber indefinitely.

Fuel injector with independent control of check valve and fuel pressurization

An actuation fluid control valve assembly for a hydraulically actuated fuel injector comprises a valve body defining a rotary valve bore and a spool valve bore. An actuator is connected with the valve body. A rotary valve member is rotatably disposed in the rotary valve bore and can be rotated in response to the actuator. A high-pressure fluid line, a spool bottom line, a check control line, and an actuator fluid drain all terminate in the rotary valve bore. At one rotary valve position, both the check control line and the spool bottom line are open to the high-pressure line. Moving the rotary valve from the first position to a second position opens the spool bottom line to the actuator fluid drain while keeping the check control line open to the high-pressure line. Moving the rotary valve from the second position to a third position opens the check control line as well as the spool bottom line to the actuator fluid drain.

Three-way actuation control of a hydraulically actuated fuel injector

A fuel injector nozzle has a housing defining a blind bore with at least one fuel injection spray orifice defined at a bottom portion of a spray tip and a guide passage defined at a top portion of the bore. An injection chamber of the bore is disposed between the orifice and the guide passage. A fuel injection passage intersects the guide passage. A needle check is slidably disposed in the blind bore for movement between a first position and a second position. In the first position, a seat portion of the check is disposed in the bore against the bottom portion of the tip while a guide portion of the check together with the guide passage define a first flow area restricting fluid flow therethrough. In the second position, the seat portion of the check is spaced from the bottom portion of the tip, and the guide portion and guide passage define a second flow area larger than the first flow area and less restrictive of flow therepast.

Fuel injector nozzle with guide to check clearance passage providing

A method of fuel injection comprises an initial step of providing an electronically-controlled hydraulically-actuated fuel injector. An on-time for the fuel injector that corresponds to a desired amount of fuel is determined. The fuel injector is activated for that on-time. Next, the actual amount of fuel injected by the fuel injector is estimated. The actual amount of fuel is compared to the desired amount of fuel. If the actual amount of fuel is substantially more than the desired amount of fuel, the on-time for a subsequent injection event is adjusted.

Adaptive control for power growth in an engine equipped with a

The fill metered hydraulically actuated fuel injection system of the present invention utilizes an actuation fluid, preferably lubricating oil, as its actuation medium that is separate and different from the fuel fluid which is actually injected into the engine. Injectors according to the present invention are hydraulically actuated and include a conventional VOP type needle check, and fuel is pressurized by a plunger driven by an intensifier piston. The end of each injection event is achieved when the plunger and piston reach the end of their strokes, which provides for an abrupt end to each injection event. An abrupt end to injection is further accomplished by providing a pressure relief passage in the plunger that relieves pressure acting on the needle check at the end of injection in order to both quickly dissipate residual fuel pressure and allow the needle check to close more rapidly. Fuel is metered into the injector either by biasing the plunger with a return spring or by pressurizing the fuel to hydraulically push the plunger in a retracting direction between injection events.

Fill metered hydraulically actuated fuel injection system and method of

A fuel injector with a hydraulically actuated needle check includes a fuel pressurization chamber positioned between a low pressure fuel supply passage and a nozzle supply bore. A portion of the low pressure fuel supply passage is in direct fluid communication with the fuel pressurization chamber via a bleed hole. A bleed pin extends into a fluid supply chamber adjacent the bleed hole. The bleed pin is movable between a first position in which the bleed hole is open and a second position in which a portion of the bleed pin closes the bleed hole when the hydraulically actuated needle check moves between its closed position and its open position, respectively. A supply valve is positioned in the low pressure fuel supply passage between the low pressure fuel supply chamber and the fuel pressurization chamber in order to prevent the back flow of fuel from the pressurization chamber into the supply passageways. When in operation, the movement of the needle check serves to open and close the bleed hole at precise times in order to both produce pilot type rate shaping at the beginning of each injection event and cause the abrupt termination of fuel flow out of the nozzle at the end of each injection event.

Fuel injector with pressure bleed-off stop

An actuator and valve assembly is disclosed which comprises an electrically-energizable actuator assembly and a device for communicating, collecting and draining damping fluid with respect to at least one cavity of the actuator assembly. If too much damping fluid remains in the actuator and valve assembly after shutdown, that damping fluid may cool off and cause slow response of the actuator and valve assembly when it is re-energized. The end result is that quick starting and/or operation of the actuator and valve assembly may be hindered, particularly under cold operating conditions. The communicating, collecting and draining means permits at least a portion of the hot damping fluid to automatically drain from the cavity after the actuator and valve assembly has been shutdown.

Damped actuator and valve assembly

An actuator and valve assembly for an electronically-controlled injector is disclosed which comprises an electrically-energizable actuator assembly and a device for communicating, collecting and draining damping fluid with respect to at least one cavity of the actuator assembly. If too much damping fluid remains in the actuator assembly after engine shutdown, that damping fluid may cool off and cause slow response of the actuator and valve assembly during cold engine starting. The end result is that quick starting and/or operation of the engine may be hindered, particularly under cold engine conditions. The communicating, collecting and draining means permits at least a portion of the hot damping fluid to automatically drain from the cavity after the engine has been shutdown.

Damped actuator and valve assembly for an electronically-controlled

In a hydraulically-actuated electronically-controlled unit injector, the viscosity of the actuating fluid used to actuate the unit injector varies with ambient temperature and affects the magnitude of pressure drops in the actuating fluid circuit. Such variations in viscosity affect the magnitude of the fuel delivery command pulsewidth and/or actuating fluid pressure required for engine startup versus that required for normal engine operation. The present invention provides an improved hydraulically-actuated electronically-controlled unit injector and methods of operation which compensate for variations in the viscosity of the actuating fluid used to hydraulically actuate a piston. The stroke of the piston is controlled electronically and/or mechanically in order to achieve an appropriate amount of fuel injection.

Hydraulically-actuated electronically-controlled unit injector having

Herein are disclosed methods of conditioning fluid, such as damping fluid, in an electronically-controlled unit injector in order to facilitate quick starting of an engine. Fluid normally used to dampen the motion of an electrical actuator assembly of the unit injector can remain in the actuator assembly after the engine is stopped. If too much fluid remains and cools off in the actuator assembly, quick starting of a cold engine may be hindered. Each of the above methods expels and/or heats up at least a portion of the remaining fluid in the actuator assembly while the engine is at rest and thereby enables quicker response of the actuator assembly when the engine is started. Such quicker response improves the fuel injection delivery capability and timing accuracy of the unit injector during engine startup.

Methods of conditioning fluid in an electronically-controlled unit

A solenoid control circuit provides energy to selected solenoids to control actuation of a control valve of a fuel injector and, hence, the timing and duration of fuel delivered to each cylinder of an internal combustion engine. The current provided to each solenoid is also controlled to provide a three tier current waveform having a pull-in current level, a hold-in current level, and an intermediate current level. Energizing the solenoid at the pull-in current level starts movement of the control valve. After the control valve starts to move, the current level is reduced to the intermediate level, which is less than the pull-in current level, but great enough to continue movement of the control valve. Further reduction of the current level to the hold-in level, which is less than either of the other current levels but sufficient to hold the control valve at the moved position. The solenoid is then de-energized and the control valve returned to its initial position to stop the flow of fuel to the engine. The foregoing is repeated for each of the other control valves of the fuel injectors to save energy and reduce the heat to be dissipated.

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Metamora, IL, United States of America

Thomas G Ausman